diff --git a/openmc/data/ace.py b/openmc/data/ace.py
index 1a56c165ef..03052bcabc 100644
--- a/openmc/data/ace.py
+++ b/openmc/data/ace.py
@@ -16,7 +16,6 @@ generates ACE-format cross sections.
 """
 
 from __future__ import division, unicode_literals
-import io
 from os import SEEK_CUR
 import struct
 import sys
@@ -164,7 +163,7 @@ class Library(object):
 
         # Determine whether file is ASCII or binary
         try:
-            fh = io.open(filename, 'rb')
+            fh = open(filename, 'rb')
             # Grab 10 lines of the library
             sb = b''.join([fh.readline() for i in range(10)])
 
@@ -173,13 +172,13 @@ class Library(object):
 
             # No exception so proceed with ASCII - reopen in non-binary
             fh.close()
-            fh = io.open(filename, 'r')
-            fh.seek(0)
-            self._read_ascii(fh, table_names, verbose)
+            with open(filename, 'r') as fh:
+                fh.seek(0)
+                self._read_ascii(fh, table_names, verbose)
         except UnicodeDecodeError:
             fh.close()
-            fh = open(filename, 'rb')
-            self._read_binary(fh, table_names, verbose)
+            with open(filename, 'rb') as fh:
+                self._read_binary(fh, table_names, verbose)
 
     def _read_binary(self, ace_file, table_names, verbose=False,
                      recl_length=4096, entries=512):
diff --git a/openmc/data/reaction.py b/openmc/data/reaction.py
index c2e1b24109..62b02048be 100644
--- a/openmc/data/reaction.py
+++ b/openmc/data/reaction.py
@@ -456,7 +456,7 @@ class Reaction(object):
             # YIELD AND ANGLE-ENERGY DISTRIBUTION
 
             # Determine multiplicity
-            ty = ace.xss[ace.jxs[5] + i_reaction - 1]
+            ty = int(ace.xss[ace.jxs[5] + i_reaction - 1])
             rx.center_of_mass = (ty < 0)
             if i_reaction < ace.nxs[5] + 1:
                 if ty != 19:
diff --git a/src/nuclide_header.F90 b/src/nuclide_header.F90
index 9f55941389..8ff83482e5 100644
--- a/src/nuclide_header.F90
+++ b/src/nuclide_header.F90
@@ -3,8 +3,9 @@ module nuclide_header
   use, intrinsic :: ISO_FORTRAN_ENV
   use, intrinsic :: ISO_C_BINDING
 
-  use hdf5
-  use h5lt,        only: h5ltpath_valid_f
+  use hdf5, only: HID_T, HSIZE_T, SIZE_T, h5iget_name_f, h5gget_info_f, &
+                  h5lget_name_by_idx_f, H5_INDEX_NAME_F, H5_ITER_INC_F
+  use h5lt, only: h5ltpath_valid_f
 
   use constants
   use dict_header, only: DictIntInt
diff --git a/src/reaction_header.F90 b/src/reaction_header.F90
index 185945563d..055dcb3923 100644
--- a/src/reaction_header.F90
+++ b/src/reaction_header.F90
@@ -1,6 +1,7 @@
 module reaction_header
 
-  use hdf5
+  use hdf5, only: HID_T, HSIZE_T, SIZE_T, h5gget_info_f, h5lget_name_by_idx_f, &
+                  H5_INDEX_NAME_F, H5_ITER_INC_F
 
   use constants,      only: MAX_WORD_LEN
   use hdf5_interface, only: read_attribute, open_group, close_group, &